1. Field of the Invention
The present invention relates to a circuit board with embedded components and a manufacturing and measuring method thereof, and more particularly, to a method for measuring the electrical parameter of at least one of the embedded components at the same time.
2. Related Art
As the rapid development of the information electronic products and high requirements for the performance and speed in the market, many information electronic products have been developed towards a trend of digital high speed, and an analog high frequency. On the other hand, the consumer electronic products also tend to meet the requirements of multifunction and being light, thin, short, small, especially for the portable electronic products of wireless communication, such as bluetooth, wireless LAN, cell phone. However, most of the hardware components of the above electronic product require a great number of passive components, which take over 75% of all the components of the system. Therefore, integrating the great number of passive components in the printed circuit board (PCB) to form embedded passives (or integral substrates) has a great market potential in increasing the density of the PCB.
The technique for the embedded passive component aims at integrating an embedded passive component and a surface mount type (SMD) into the circuit board. At least the following advantages can be achieved by integrating the embedded passive components into the circuit board. (1) The manufacturing cost is reduced. (2) The density of the circuit board is increased. Recently, the common PCB technique has gradually been used in a multi-layer printing structure, thus, the use of an original two-dimensional area is converted into a three-dimensional design, so as to reduce the volume of the product. (3) Welding points for the circuit are reduced, so as to enhance the reliability of the whole product. (4) The embedded component has a low humidity, which is protected from being corrosion.
The current technique for manufacturing embedded components includes the low temperature cofired ceramics (LTCC) process and the process for fabricating the functional substrate developed by Chinese Industrial Technology Research Institute, which greatly enhances the adaptability and the manufacturing stability of the embedded components.
Therefore, in the conventional art, an important impedance control line is provided in a high frequency electronic system for measuring the circuit board with the embedded component, i.e., an impedance control line is fabricated on the edge of the circuit board to measure the process variances of the line width, material parameter, and laminating thickness after being fabricated, and thereby observing whether the impedance of the transmission line is affected or not, and further affecting the transmission efficiency of the system, but the electrical parameter of the fabricated embedded component cannot be accurately measured. Alternatively, through a circuit design method, the mechanism of making the transmission line to be an open circuit, short circuit, or break circuit is provided, which can only measure whether the basic transmission line is communicated or not, thus being limited in function.
Moreover, in the conventional art, the measurement of the embedded components is carried on by taking a single embedded component for a single part measurement, i.e., the electrical parameter of only one embedded component can be measured at one time. Therefore, the conventional measuring method is time and labor consuming, thus the fabricating cost is increased and the production capability is reduced.